are there any open university in India with out any entrance exams
There is no such universities which take admissions directly without any exam score. However, if you are asking for separate entrance exam/ university specific entrance exams, then yes, there are numerous universities which are taking admissions on the basis of 12th board percentage this year. Some of them used to take admissions on the basis of their own entrance exams, but due to COVID-19 pandemic, they have cancelled their exams and will be taking admissions on the basis of 12th percentage.
Hope it helps.